Red Dog mine
Encyclopedia
The Red Dog mine is a zinc
and lead mine
located in a remote region of the Arctic, within the boundaries of the Red Dog Mine
census-designated place
in the Northwest Arctic Borough
of the U.S. state
of Alaska
.
The mine is the world's largest producer of zinc and has the world's largest zinc reserves. Red Dog accounts for 10% of the world's zinc production. Red Dog accounted for 55% of the mineral value produced in Alaska in 2008. In 2008 the mine produced 515,200 metric tons (507,100 LT
; 567,900 ST
) of zinc, 122,600 metric tons (120,700 LT; 135,100 ST) of lead, and 283 metric tons (9,100,000 ozt
) of silver, for a total metal value of over one billion dollars. At the end of 2008 the mine had reserves of 61,400,000 metric tons (60,400,000 LT; 67,700,000 ST) of zinc at a grade of 17.1% and 61,400,000 tonnes (60,400,000 LT; 67,700,000 ST) of lead at a grade of 4.5%, as well as significant additional zinc and lead in the less well-measured resource category.
Red Dog is located on land owned by the NANA Regional Corporation
and is operated by the commercial mining company Teck Resources in partnership with NANA Development Corporation
. Ore concentrate taken from the mine is trucked westward to a shipping facility on the Chukchi Sea
and stored there until the shipping season.
The mine, which produces from an open pit
, is expected to exhaust its currently-permitted ore in 2012. Teck Cominco has applied for permits to expand mining into the Aqqaluk orebody, immediately adjacent to the current pit, containing an additional 56 million metric tons (62 million short tons) of lead and zinc ore. The expansion would keep the mine operating until 2031.
geologist sampled rocks and stream sediments in the area, including samples from the future site of the Red Dog mine, and named Red Dog Creek after the red dog of local pilot Bob Baker, a frequent flier in the area (Tailleur; USGS Open File 70-319). In the mid and late 1970s, interest in the area from major mining companies and NANA intensified. In 1980 the Alaska National Interest Lands Conservation Act
(ANILCA) became law and NANA officially selected the land underlying the deposits. Drill exploration of the deposits began in 1980, by Cominco American. In 1982 NANA and Cominco American (a mining company that had staked the land, and later became Teck Cominco) signed an agreement to develop the deposit. In 1986 the State of Alaska agreed to fund and take ownership of a road (DeLong Mts. Transportation System) from Red Dog to the coast, and a shallow-water port site. Also in 1986, residents of Kotzebue
and 10 other area villages voted to form the Northwest Arctic Borough, to be economically based on taxing the Red Dog mine. Construction of the road, port site, and mine began in July 1987. Mine operations commenced in December 1989.
of 1971 (ANSCA), which created NANA and the other native corporations in Alaska, NANA must share approximately half of its profits from natural resources with the other eleven land-based regional native corporations. If the mine remains profitable at the current level, this will mean a distribution of several hundred million dollars a year of mine profits to the regional native corporations.
black shale and carbonates.
Mesozoic
mountain-building tectonic events (i.e. the Brookian orogen that built the Brooks Range
) deformed and thrust fault
ed the sedimentary strata that host the deposits and the deposits themselves. Subsequent uplift and erosion exposed parts of the deposits at today's earth surface.
Red Dog is an example of a sedimentary exhalative deposit
, with the zinc
-lead
ore
considered to have been deposited on the sea floor as a strata of sulfide sediment. Zinc, lead, silver, and barium were deposited in black muds and carbonates on or beneath the seafloor, in a deep quiet ocean basin, some 338 million years ago in the Mississippian period.
Fluids probably percolated
through a huge mass (hundreds of square kilometers) of sediments. The nature of the fluids caused them to absorb and concentrate trace amounts of zinc and lead contained in the rocks the fluids were passing through. These metals were then caused to precipitate, by chemical or biological or physical agents, from the fluid onto or into the seafloor to form the Red Dog deposits.
One model holds that very saline brines formed in a restricted ocean basin within a hundred kilometers of the site of the Red Dog deposits. The brine fluid infiltrated the subsurface and was tectonically
pumped through the rock mass, becoming enriched in metals as it stripped those metals from the rocks it passed through. The fluid traveled several kilometers below the earth's surface. The fluid eventually reemerged through fault systems focused on the location of the Red Dog deposits, in a manner somewhat similar to the process surrounding black smokers
.
about 90 miles (144 km) north of Kotzebue
and 55 miles (88 km) from the Chukchi Sea
.
, has only 11 communities and a population of only 7,208 people, 84% of which are native or part native, and 40% of which report speaking native at home. No roads connect the communities. The nearest permanent settlements to the mine, roughly 60 miles (96.6 km) west and 50 miles (80.5 km) south respectively, are the villages of Kivalina, population 377, and Noatak, population 428, at the 2000 census
.
Although native populations have historically used areas around the mine and port for seasonal food-gathering there are no permanent residents at the mine or port site. The workforce consists of about 460 employees and contractors, of which somewhat more than half will be on-site at any given time. All staff work on a rotation, most on either a 4 weeks on/2 weeks off or 2 week on/1 week off schedule. At the mine, everybody stays in the single large housing unit, tucked in among the process buildings near the edge of the open pit. A small portion of the work force stays at the port site. NANA shareholders comprise 56% of the mine's workforce.
The Red Dog mine provides over a quarter of the borough's wage and salary payroll. While many of the borough's residents benefit from the mine and associated economic activities, virtually all of the borough's residents rely on subsistence activities which are dependent on a healthy environment.
(EPA), Red Dog Mine creates more toxic waste than any other operation in the United States. But, almost all (over 99%) of the "toxic waste" reported by Red Dog is just rocks (waste rock and tailings) which naturally contain >2% sulfide minerals, thus making them reportable as "toxic waste". All of the waste rock and tailings material remains in permanent disposal on-site, contained, and treated as necessary by the mine operations. The EPA notes about Red Dog's rank, "No conclusions on the potential risks can be made based solely on this information."
Leaching of metals and acids from waste rocks into the environment is a valid concern. The waste rock piles are contained and all runoff water is monitored and treated to water quality standards. Monitoring, and mitigation if necessary, will need to continue throughout the mine life and for many decades after mine closure
.
"Concentrations of Cd and Pb...exceed medians (and in most cases maxima) from all 28
countries in the Nordic moss monitoring program, including many of the most polluted
countries in Central and Eastern Europe and all areas of western Russia."
That sentence is often misunderstood as a comparison of levels of pollution at Red Dog to levels of pollution at industrial sites elsewhere. The 2001 NPS study does not compare
pollution at Red Dog to pollution at polluted sites in Europe: it does not conclude that the
Red Dog area is more polluted than the worst-polluted areas of Central and Eastern Europe or western Russia. There are hundreds of sites in Central and Eastern Europe and western Russia that are incomparably more polluted than the Red Dog area, e.g., Dzerzinsk and Norilsk in Russia, Chernobyl in Ukraine, and Baia Mare in Romania
The statement quoted above compares samples collected in 2001 adjacent to Red Dog industrial activity to samples collected for the Nordic moss monitoring program: samples which are deliberately collected as far from urban and industrial areas as possible. The Nordic moss monitoring program follows a protocol that demands that samples be collected at least 300 meters from a road and that samples be collected in non-urban areas. Significantly, samples for the study at Red Dog included the loose dust on the moss, while the Nordic moss monitoring program moss samples were shaken to remove dust.
The 2001 NPS study also collected and analyzed soil samples at the moss-collection sites: no elevated levels of lead or cadmium were detected. Additional studies conclude that the concentrations of heavy metals detected in water, soil, caribou, fish, and berry samples collected from the Red Dog mine area do not pose a public health hazard. It is generally agreed that years of operation of tarp-top haul trucks (one every 15 minutes) carrying lead-zinc concentrate resulted in lead and cadmium-bearing dust contamination along the edges of the haul road. Fortunately this poor practice has not resulted in a threat to human safety. The entire concentrate-haulage system has been improved, including tight-fitting seals on side-dump trucks and enclosure of conveyor belts at the port site.
water supplies have shown no elevated levels of lead or other heavy metals. Blood tests of mine workers, for lead levels, are done regularly. A few mine workers have experienced elevated lead levels.
is contracted by the mine to fly other mine workers out of Anchorage. Until 2007, gravel-strip capable Boeing 737-200
Combi
aircraft were used. These ships have a cargo door in the front part of the aircraft and a separate rear passenger cabin. In 2005 the runway was paved, in anticipation of newer Boeing 737-400 Combi aircraft which are not equipped to land on gravel.
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
and lead mine
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
located in a remote region of the Arctic, within the boundaries of the Red Dog Mine
Red Dog Mine, Alaska
Red Dog Mine is a census-designated place in the Northwest Arctic Borough of the U.S. state of Alaska. The population was 32 at the 2000 census.-Economy:...
census-designated place
Census-designated place
A census-designated place is a concentration of population identified by the United States Census Bureau for statistical purposes. CDPs are delineated for each decennial census as the statistical counterparts of incorporated places such as cities, towns and villages...
in the Northwest Arctic Borough
Northwest Arctic Borough, Alaska
-National protected areas:* Alaska Maritime National Wildlife Refuge ** Chamisso Wilderness* Bering Land Bridge National Preserve * Cape Krusenstern National Monument* Gates of the Arctic National Park and Preserve...
of the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
.
The mine is the world's largest producer of zinc and has the world's largest zinc reserves. Red Dog accounts for 10% of the world's zinc production. Red Dog accounted for 55% of the mineral value produced in Alaska in 2008. In 2008 the mine produced 515,200 metric tons (507,100 LT
Long ton
Long ton is the name for the unit called the "ton" in the avoirdupois or Imperial system of measurements, as used in the United Kingdom and several other Commonwealth countries. It has been mostly replaced by the tonne, and in the United States by the short ton...
; 567,900 ST
Short ton
The short ton is a unit of mass equal to . In the United States it is often called simply ton without distinguishing it from the metric ton or the long ton ; rather, the other two are specifically noted. There are, however, some U.S...
) of zinc, 122,600 metric tons (120,700 LT; 135,100 ST) of lead, and 283 metric tons (9,100,000 ozt
Troy ounce
The troy ounce is a unit of imperial measure. In the present day it is most commonly used to gauge the weight of precious metals. One troy ounce is nowadays defined as exactly 0.0311034768 kg = 31.1034768 g. There are approximately 32.1507466 troy oz in 1 kg...
) of silver, for a total metal value of over one billion dollars. At the end of 2008 the mine had reserves of 61,400,000 metric tons (60,400,000 LT; 67,700,000 ST) of zinc at a grade of 17.1% and 61,400,000 tonnes (60,400,000 LT; 67,700,000 ST) of lead at a grade of 4.5%, as well as significant additional zinc and lead in the less well-measured resource category.
Red Dog is located on land owned by the NANA Regional Corporation
NANA Regional Corporation
is one of thirteen Alaska Native Regional Corporations created under the Alaska Native Claims Settlement Act of 1971 in settlement of Alaska Native land claims. NANA was incorporated in Alaska on June 7, 1972. NANA is a for-profit corporation with a land base in the Kotzebue area in northwest...
and is operated by the commercial mining company Teck Resources in partnership with NANA Development Corporation
NANA Development Corporation
NANA Development Corporation headquartered in Anchorage, Alaska, is owned by NANA Regional Corporation—an Alaska Native Corporation formed under provisions of the Alaska Native Claims Settlement Act —and functions as the latter’s business arm.-History:...
. Ore concentrate taken from the mine is trucked westward to a shipping facility on the Chukchi Sea
Chukchi Sea
Chukchi Sea is a marginal sea of the Arctic Ocean. It is bounded on the west by the De Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, beyond which lies the Beaufort Sea. The Bering Strait forms its southernmost limit and connects it to the Bering Sea and the Pacific...
and stored there until the shipping season.
The mine, which produces from an open pit
Open-pit mining
Open-pit mining or opencast mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow....
, is expected to exhaust its currently-permitted ore in 2012. Teck Cominco has applied for permits to expand mining into the Aqqaluk orebody, immediately adjacent to the current pit, containing an additional 56 million metric tons (62 million short tons) of lead and zinc ore. The expansion would keep the mine operating until 2031.
History
In the mid-1950s, pilots and geologists noted mineral staining in the region. In 1968 a U.S. Geological SurveyUnited States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
geologist sampled rocks and stream sediments in the area, including samples from the future site of the Red Dog mine, and named Red Dog Creek after the red dog of local pilot Bob Baker, a frequent flier in the area (Tailleur; USGS Open File 70-319). In the mid and late 1970s, interest in the area from major mining companies and NANA intensified. In 1980 the Alaska National Interest Lands Conservation Act
Alaska National Interest Lands Conservation Act
The Alaska National Interest Lands Conservation Act was a United States federal law passed in 1980 by the U.S. Congress and signed into law by President Jimmy Carter on December 2 of that year....
(ANILCA) became law and NANA officially selected the land underlying the deposits. Drill exploration of the deposits began in 1980, by Cominco American. In 1982 NANA and Cominco American (a mining company that had staked the land, and later became Teck Cominco) signed an agreement to develop the deposit. In 1986 the State of Alaska agreed to fund and take ownership of a road (DeLong Mts. Transportation System) from Red Dog to the coast, and a shallow-water port site. Also in 1986, residents of Kotzebue
Kotzebue, Alaska
As of the census of 2000, there were 3,082 people, 889 households, and 656 families residing in the city. The population density was 114.1 people per square mile . There were 1,007 housing units at an average density of 37.3 per square mile...
and 10 other area villages voted to form the Northwest Arctic Borough, to be economically based on taxing the Red Dog mine. Construction of the road, port site, and mine began in July 1987. Mine operations commenced in December 1989.
Economics
Under the terms of the Teck Cominco/NANA agreement, NANA received royalties of 4.5% until the capital costs of the mine were recovered, which occurred in late 2007. At this point, the royalty due to NANA increased to 25%, and will increase by an additional 5% every year, to a maximum of 50%. Under the terms of the Alaska Native Claims Settlement ActAlaska Native Claims Settlement Act
The Alaska Native Claims Settlement Act, commonly abbreviated ANCSA, was signed into law by President Richard M. Nixon on December 23, 1971, the largest land claims settlement in United States history. ANCSA was intended to resolve the long-standing issues surrounding aboriginal land claims in...
of 1971 (ANSCA), which created NANA and the other native corporations in Alaska, NANA must share approximately half of its profits from natural resources with the other eleven land-based regional native corporations. If the mine remains profitable at the current level, this will mean a distribution of several hundred million dollars a year of mine profits to the regional native corporations.
Geology
The Red Dog area has the world's largest known zinc deposits: the four at Red Dog as well as Anarraak and Su-Lik, respectively 10 and 18 km (6.2 and 11.2 ) northwest. They are stratiform massive sulfide bodies hosted in CarboniferousCarboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
black shale and carbonates.
Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
mountain-building tectonic events (i.e. the Brookian orogen that built the Brooks Range
Brooks Range
The Brooks Range is a mountain range in far northern North America. It stretches from west to east across northern Alaska and into Canada's Yukon Territory, a total distance of about 1100 km . The mountains top out at over 2,700 m . The range is believed to be approximately 126 million years old...
) deformed and thrust fault
Thrust fault
A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...
ed the sedimentary strata that host the deposits and the deposits themselves. Subsequent uplift and erosion exposed parts of the deposits at today's earth surface.
Red Dog is an example of a sedimentary exhalative deposit
Sedimentary exhalative deposits
Sedimentary exhalative deposits are ore deposits which are interpreted to have been formed by release of ore-bearing hydrothermal fluids into a water reservoir , resulting in the precipitation of stratiform ore....
, with the zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
-lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
considered to have been deposited on the sea floor as a strata of sulfide sediment. Zinc, lead, silver, and barium were deposited in black muds and carbonates on or beneath the seafloor, in a deep quiet ocean basin, some 338 million years ago in the Mississippian period.
Fluids probably percolated
Percolation
In physics, chemistry and materials science, percolation concerns the movement and filtering of fluids through porous materials...
through a huge mass (hundreds of square kilometers) of sediments. The nature of the fluids caused them to absorb and concentrate trace amounts of zinc and lead contained in the rocks the fluids were passing through. These metals were then caused to precipitate, by chemical or biological or physical agents, from the fluid onto or into the seafloor to form the Red Dog deposits.
One model holds that very saline brines formed in a restricted ocean basin within a hundred kilometers of the site of the Red Dog deposits. The brine fluid infiltrated the subsurface and was tectonically
Tectonics
Tectonics is a field of study within geology concerned generally with the structures within the lithosphere of the Earth and particularly with the forces and movements that have operated in a region to create these structures.Tectonics is concerned with the orogenies and tectonic development of...
pumped through the rock mass, becoming enriched in metals as it stripped those metals from the rocks it passed through. The fluid traveled several kilometers below the earth's surface. The fluid eventually reemerged through fault systems focused on the location of the Red Dog deposits, in a manner somewhat similar to the process surrounding black smokers
Hydrothermal vent
A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart, ocean basins, and hotspots. Hydrothermal vents exist because the earth is both...
.
Reserves and resources
Ore bodies and contained zinc at Red Dog consist of;- Main pit ore body with 19.5 million metric tons (21.5 million short tons)of ore containing 20.5% zinc. The figures represent the orebody before mining began in 1989. This is the currently permitted area of active mining, which is expected to be mined out by 2012. The ultimate size of this pit will be 5,200 ft by 3,000 ft by 400 ft (1,600 m x 900 m x 120 m) deep.
- Aqqaluk ore body with 55.7 million metric tons (61.4 million short tons) at 16% zinc. This is adjacent to the Main pit. It is well understood geologically and metallurgically. A Supplemental Environmental Impact Statement is expected to be produced in 2008 as part of the process of permitting the development of this ore body. Most of the waste rock from this operation is expected to be placed in the depleted Main pit.
- Qanaiyaq ore body with 4.7 million metric tons (5.2 million short tons) at 23.7% zinc. Also an open-pit target, studies of the ore characteristics of Qanaiyaq continue.
- The Paalaaq ore body with 13 million metric tons (14.3 million short tons) at 15% zinc and the Anarraaq ore body with 17.2 million metric tons (19.0 million short tons) at 15% zinc are both deep underground and will be accessed by tunnels and shafts, if they are eventually mined.
Geography
Red Dog mine is located at 68°4′19"N 162°52′34"W (68.071989, -162.876044). It is in the DeLong Mountains in the remote western Brooks RangeBrooks Range
The Brooks Range is a mountain range in far northern North America. It stretches from west to east across northern Alaska and into Canada's Yukon Territory, a total distance of about 1100 km . The mountains top out at over 2,700 m . The range is believed to be approximately 126 million years old...
about 90 miles (144 km) north of Kotzebue
Kotzebue, Alaska
As of the census of 2000, there were 3,082 people, 889 households, and 656 families residing in the city. The population density was 114.1 people per square mile . There were 1,007 housing units at an average density of 37.3 per square mile...
and 55 miles (88 km) from the Chukchi Sea
Chukchi Sea
Chukchi Sea is a marginal sea of the Arctic Ocean. It is bounded on the west by the De Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, beyond which lies the Beaufort Sea. The Bering Strait forms its southernmost limit and connects it to the Bering Sea and the Pacific...
.
Regional
The mine lies within the Northwest Arctic Borough, the boundaries of which are exactly coincident with the boundaries of the NANA Regional Corporation. The borough, which is approximately the size of IndianaIndiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
, has only 11 communities and a population of only 7,208 people, 84% of which are native or part native, and 40% of which report speaking native at home. No roads connect the communities. The nearest permanent settlements to the mine, roughly 60 miles (96.6 km) west and 50 miles (80.5 km) south respectively, are the villages of Kivalina, population 377, and Noatak, population 428, at the 2000 census
United States Census, 2000
The Twenty-second United States Census, known as Census 2000 and conducted by the Census Bureau, determined the resident population of the United States on April 1, 2000, to be 281,421,906, an increase of 13.2% over the 248,709,873 persons enumerated during the 1990 Census...
.
Although native populations have historically used areas around the mine and port for seasonal food-gathering there are no permanent residents at the mine or port site. The workforce consists of about 460 employees and contractors, of which somewhat more than half will be on-site at any given time. All staff work on a rotation, most on either a 4 weeks on/2 weeks off or 2 week on/1 week off schedule. At the mine, everybody stays in the single large housing unit, tucked in among the process buildings near the edge of the open pit. A small portion of the work force stays at the port site. NANA shareholders comprise 56% of the mine's workforce.
The Red Dog mine provides over a quarter of the borough's wage and salary payroll. While many of the borough's residents benefit from the mine and associated economic activities, virtually all of the borough's residents rely on subsistence activities which are dependent on a healthy environment.
Environmental concerns
Before discovery of the mineral deposits at Red Dog, the creek draining the deposit was too toxic to support life. It now meets drinking-water standards. On June 13, 2007 the State of Alaska removed two creeks (Red Dog Creek and Ikalukrok Creek) near the Red Dog mine in Northwest Alaska from the most-polluted waters list with EPA's approval. The mine discharges treated water into Red Dog Creek, a tributary of Ikalukrok Creek. Pre-mining studies on Red Dog Creek revealed naturally high concentrations of cadmium, lead, zinc, aluminum, and other metals. Before mining began, aquatic life uses were not present in the main stem of Red Dog Creek because of the natural toxic concentrations and low pH. After mining began, year-round release of treated mine wastewater allowed a population of Arctic Grayling to establish themselves in Red Dog Creek. That fish population is now protected by regulations.Toxic waste releases
According to the U.S. Environmental Protection AgencyUnited States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
(EPA), Red Dog Mine creates more toxic waste than any other operation in the United States. But, almost all (over 99%) of the "toxic waste" reported by Red Dog is just rocks (waste rock and tailings) which naturally contain >2% sulfide minerals, thus making them reportable as "toxic waste". All of the waste rock and tailings material remains in permanent disposal on-site, contained, and treated as necessary by the mine operations. The EPA notes about Red Dog's rank, "No conclusions on the potential risks can be made based solely on this information."
Leaching of metals and acids from waste rocks into the environment is a valid concern. The waste rock piles are contained and all runoff water is monitored and treated to water quality standards. Monitoring, and mitigation if necessary, will need to continue throughout the mine life and for many decades after mine closure
Mine closure
Mine closure is the period of time when the ore-extracting activities of a mine have ceased, and final decommissioning and mine reclamation are being completed. It is generally associated with reduced employment levels, which can have a significant negative impact on local economies...
.
Heavy metals (lead and cadmium) in mosses adjacent to the haul road
A 2001 study for the National Park Service (NPS) reports in its Executive Summary that,"Concentrations of Cd and Pb...exceed medians (and in most cases maxima) from all 28
countries in the Nordic moss monitoring program, including many of the most polluted
countries in Central and Eastern Europe and all areas of western Russia."
That sentence is often misunderstood as a comparison of levels of pollution at Red Dog to levels of pollution at industrial sites elsewhere. The 2001 NPS study does not compare
pollution at Red Dog to pollution at polluted sites in Europe: it does not conclude that the
Red Dog area is more polluted than the worst-polluted areas of Central and Eastern Europe or western Russia. There are hundreds of sites in Central and Eastern Europe and western Russia that are incomparably more polluted than the Red Dog area, e.g., Dzerzinsk and Norilsk in Russia, Chernobyl in Ukraine, and Baia Mare in Romania
The statement quoted above compares samples collected in 2001 adjacent to Red Dog industrial activity to samples collected for the Nordic moss monitoring program: samples which are deliberately collected as far from urban and industrial areas as possible. The Nordic moss monitoring program follows a protocol that demands that samples be collected at least 300 meters from a road and that samples be collected in non-urban areas. Significantly, samples for the study at Red Dog included the loose dust on the moss, while the Nordic moss monitoring program moss samples were shaken to remove dust.
The 2001 NPS study also collected and analyzed soil samples at the moss-collection sites: no elevated levels of lead or cadmium were detected. Additional studies conclude that the concentrations of heavy metals detected in water, soil, caribou, fish, and berry samples collected from the Red Dog mine area do not pose a public health hazard. It is generally agreed that years of operation of tarp-top haul trucks (one every 15 minutes) carrying lead-zinc concentrate resulted in lead and cadmium-bearing dust contamination along the edges of the haul road. Fortunately this poor practice has not resulted in a threat to human safety. The entire concentrate-haulage system has been improved, including tight-fitting seals on side-dump trucks and enclosure of conveyor belts at the port site.
Measurable direct effects of the mine on human health
Repeated testing of blood samples from area villagers, and repeated testing of area villagewater supplies have shown no elevated levels of lead or other heavy metals. Blood tests of mine workers, for lead levels, are done regularly. A few mine workers have experienced elevated lead levels.
Proposed port site expansion
Local inhabitants have expressed concerns that the proposed expansion of docking facilities may detrimentally change the migratory patterns of marine life.Transportation
A 52 miles (84 km) long haul road connects the mine to the mine's port site on the Chukchi Sea. The mine and port site are accessible only by air, except during the 100-day shipping season. Mine workers from remote villages in the region are ferried to the mine on small aircraft. Alaska AirlinesAlaska Airlines
Alaska Airlines is an airline based in the Seattle suburb of SeaTac, Washington in the United States. The airline originated in 1932 as McGee Airways. After many mergers with and acquisitions of other airlines, including Star Air Service, it became known as Alaska Airlines in 1944...
is contracted by the mine to fly other mine workers out of Anchorage. Until 2007, gravel-strip capable Boeing 737-200
Boeing 737
The Boeing 737 is a short- to medium-range, twin-engine narrow-body jet airliner. Originally developed as a shorter, lower-cost twin-engine airliner derived from Boeing's 707 and 727, the 737 has developed into a family of nine passenger models with a capacity of 85 to 215 passengers...
Combi
Combi
In commercial aviation, the term combi refers to versions of various aircraft that can be used for either passenger, as an airliner would, or cargo duties, as a freighter would, and often have a partition in the aircraft cabin to allow both uses at once...
aircraft were used. These ships have a cargo door in the front part of the aircraft and a separate rear passenger cabin. In 2005 the runway was paved, in anticipation of newer Boeing 737-400 Combi aircraft which are not equipped to land on gravel.
See also
- Sedimentary exhalative depositsSedimentary exhalative depositsSedimentary exhalative deposits are ore deposits which are interpreted to have been formed by release of ore-bearing hydrothermal fluids into a water reservoir , resulting in the precipitation of stratiform ore....
- Acid mine drainageAcid mine drainageAcid mine drainage , or acid rock drainage , refers to the outflow of acidic water from metal mines or coal mines. However, other areas where the earth has been disturbed may also contribute acid rock drainage to the environment...
- Land rehabilitationLand rehabilitationLand rehabilitation is the process of returning the land in a given area to some degree of its former state, after some process has resulted in its damage...
- Open-pit miningOpen-pit miningOpen-pit mining or opencast mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow....
- MetallurgyMetallurgyMetallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use...